Technical Field
The present disclosure is directed to a semiconductor package and a method of manufacturing the semiconductor package having leads that include at least one interlocking portion to prevent lead pull out.
Description of the Related Art
As consumer demand increases for semiconductor packages, manufacturers face significant challenges to manufacture and form packages that are able to withstand external stresses and forces that may break the semiconductor package. For example, external stresses may be a result from being dropped or external forces may be a result of transporting the semiconductor packages. These external stresses and forces may result in lead pull out causing semiconductor packages to be less efficient or completely fail. Additionally, as electronic devices get thinner, manufacturers face significant challenges to reduce the size of semiconductor packages while avoiding defects in the packages that may lead to short circuiting or other failures. One such cause of short circuiting, resulting in a faulty semiconductor package, is wire to wire short circuiting. Another cause of short circuiting is wire to die short circuiting.
One method of forming a semiconductor package is by starting with a lead frame made of a conductive material with a uniform thickness and blanket plating it on both sides with a selective chemically resistant conductive material forming layers of the selective chemically resistant conductive material. Then portions of the layers of selective chemically resistant conductive material are removed to expose portions of the conductive material and leave areas of the conductive material covered by the selective chemically resistant conductive material. The conductive material with the selective chemically resistant conductive material areas is then etched on one side with a chemical that will etch the lead frame, but not the selective chemically resistant conductive material. This chemical etching creates individual leads. After the first chemical etching, a die is coupled to the lead frame. Then electrical connections are formed by wires between the die and the leads. After the electrical connections are formed and the die is in place, a molding compound is placed encasing the die, the electrical connections, and the leads. After the molding compound is allowed to cure, a chemical back-etching is done to the conductive material to physically and electrically separate the leads and the die pads from each other. This may be done on a large scale to produce hundreds, thousands, or any number of semiconductor packages in a single manufacturing batch.
In some instances, when utilizing the above method the etching of the lead frame and leads may result in a lead that has a cross section of the type as illustrated in FIG. 2C.